2*72 BULLETIN 56, UNITED STATES NATIONAL MUSEUM. 



U.S.N.M.), killed August 31, 1893, had completed the post-breed- 

 ing coat. An immature female (No. 58901 U.S.N.M.), September 

 7, 1893, is in complete summer pelage and of a brighter orange-buff 

 than any other in the series. In this specimen the permanent pre- 

 molar is just replacing its predecessor and the squirrel is two-thirdS 

 grown. The three remaining specimens (adults; September 5 to 



29, 1893) illustrate the au- 

 tumnal chalige. 



Measurements (average of 

 8 adiilt specimens from San 

 Luis Mountains, near Monu- 

 ment No. 65).— Length, 554 

 mm.; tail to end of verte- 

 brae, 279 ; tail to end of hairs, 

 359; expanse of tail hairs, 

 160; ear from crown, 24; 

 ear from notch, 33; hind 

 foot, 77. 



r anial characters. — 

 Skull (fig. 43) similar to 

 that typical of Sciurus rwfi- 

 venter, but relatively broad 

 (66 by 37 mm. in S. rufl- 

 venter against 65 by 37 in 

 S. apache). It is low, flat- 

 tened superiorly,, with the 

 nasals very flat; rostrum 

 rather ■ high ; audital bullae 

 much larger than in S. nif,- 

 venter; ' incisive foramen 

 and interpterygoid fossa 

 long, as in the fox squirrel 

 group. 



Habits and local distribution. — Dr. A. K. Fisher collected a speci- 

 men of the Apache squirrel in the Chiricahua Mountains, south- 

 eastern Arizona. I have only seen it in the San Luis Mountains, 

 in the vicinity of Monument No. 65, where it ranged from 1,700 to 

 2,100 meters in altitude. Nests were seen in the oak zone from 1,700 

 to 1,800 meters. It was not observed at the summit. Its favorite 

 food appeared to be the acorn of Quercus hypoleuca, and most of 

 the nests were placed in trees of that species. A female shot in Tur- 

 key Canyon, San Luis Mountains, Chihuahua, Mexico, July 11, 1892, 

 contained 3 fetuses, whose envelopes measured 3^ inches in greatest 

 diameter. Its habits reminded roe much of those of the fox squirrel. 



Fie. 43.— SciuEus APACHE. San Luis Mountains, near 

 Monument No. 65. (Cat. No. 35692, U.S.N.M.) a. Doe- 

 sal view; b, VENTAL view; c, lateral view. 



